2019-03-21T17:30:55Z1,5-hydride shift of alkenyl sulfoximine/[4+3] cycloaddition and ring opening/novel hydrazine synthesis from Tröger's base analogueshttps://hdl.handle.net/10355/36669
1,5-hydride shift of alkenyl sulfoximine/[4+3] cycloaddition and ring opening/novel hydrazine synthesis from Tröger's base analogues
Gao, Xuefeng, 1980-
Three synthetic methodologies are studied in details in this dissertation. For 1,5-hydride shift of alkenyl sulfoximine methodology, the reaction mechanism was studied using deuterium labeling. An uncommon 6-endo-trig 1,5-hydride shift process was discovered. The scope and limitation were studied using N-alkyl, N-allyl, and N-benzyl-substituted S-alkenyl sulfoximines. N-H-S-alkyl sulfoximines, four- and six-membered heterocyclic rings and a new class of chiral dienes were obtained. In [4+3] cycloaddition and ring opening chapter, we demonstrated an ene-like reaction using a symmetric oxyallylic cation can provide α-substituted cyclopentenones. Enantio pure products are potentially accessible by this method. [4+3] Cycloaddition of the symmetric oxyallylic cation with substituted furans, and the ring-opening process of the resulting 8-oxabicyclo[3.2.1]oct-6-en-3-one were also studied. The reaction conditions and scope were investigated. An acid-catalyzed mechanism was proposed for the ring-opening process. In the third chapter, we showed some interesting tetracyclic hydrazine compounds can be synthesized from Tröger's base analogues 1 by using the Polonovski reaction conditions. An oxidative rearrangement mechanism was proposed. Products were not obtained from some steric hindered Tröger's base analogues.
Title from PDF of title page (University of Missouri--Columbia, viewed on July 29, 2013).; The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.; Dissertation advisor: Dr. Michael Harmata; Includes bibliographical references.; Vita.; Ph. D. University of Missouri--Columbia 2012.; Dissertations, Academic -- University of Missouri--Columbia -- Chemistry; "July 2012"
2012-01-01T00:00:00Z11-amino-1 undecene-covered SI (100) and GE (100) surfaceshttps://hdl.handle.net/10355/15281
11-amino-1 undecene-covered SI (100) and GE (100) surfaces
Liu, Jing
Due to the similar properties and structures of silicon and germanium surfaces, they have similar methods of passivation and organic functionalizaiton reactions. The formation of organic monolayers on semiconductor surfaces has recently become an area of intense investigation. One important motivation is the need to control electronic properties by covalently attaching molecules to the semiconductor surface. Another driving motivation is to incorporate organic molecular properties, such as chemical affinity, flexibility, conductivity, and chirality for developing biomedical sensors. The research described herein investigates the hydrogen, t-BoC, and amine terminated Si(100) or Ge(100) surfaces, and to determine the elemental percentages of carbon, nitrogen, oxygen and silicon/ germanium present at the semiconductor surface using Xray photoelectron spectroscopy (XPS).
Title from PDF of title page (University of Missouri--Columbia, viewed on September 13, 2012).; The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.; Thesis advisor: Dr. C. Michael Greenlief; Includes bibliographical references.; Vita.; M.S. University of Missouri--Columbia 2012.; Dissertations, Academic -- University of Missouri--Columbia -- Chemistry.; "May 2012"
2012-01-01T00:00:00Z2,1-Benzothiazines: preparation and reactivityhttps://hdl.handle.net/10355/8309
2,1-Benzothiazines: preparation and reactivity
Calkins, Nathan L., 1982-
The synthesis of chiral ligands to tune the reactivity and stereoselectivity of many catalytic asymmetric reactions has been given considerable attention in synthetic organic chemistry over the past decade. This report will show the results of efforts toward the syntheses of several families of enantiomerically pure 2,1-benzothiazine ligands. These ligands are unique in that they contain a chiral sulfoximine. Several 2,1-benzothiazine ligands were prepared in single one-pot syntheses and others in as many as five or more steps for larger heterocycles. An optimized synthetic route will be shown for a very well known Buchwald Hartwig N-arylation of sulfoximines and haloarenes. The synthetic procedure for the N-arylation of sulfoximines synthetic procedure has virtually been unchanged since its introduction in 1998. The new synthesis herein has dramatically improved reaction time and scope for the N-arylation of aryl bromides and aryl chlorides. Until now, aryl chloride based N-arylations gave extremely poor conversions when attempted thermally. Lastly, unsubstituted and 4-phenyl substituted 2,1-benzothiazine lithiation reactivity will be discussed for the sulfoximine stabilized lithium vinyl carbanions. Mono- and di-substitutions are now synthetically possible. New synthetic strategies for accessing the ortho-S-phenyl ring as a viable carbanion will also be shown.
Title from PDF of title page (University of Missouri--Columbia, viewed on May 24, 2010).; The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file.; Dissertation advisor: Dr. Michael Harmata.; Vita.; Includes bibliographical references.; Ph. D. University of Missouri--Columbia 2010.; Dissertations, Academic -- University of Missouri--Columbia -- Chemistry.
2010-01-01T00:00:00Z[2,3]-Sigmatropic rearrangement of propargylic sulfinates ; Regiodivergent synthesis of 1- and 2 arylsulfonyl 1,3-dienes, and III. Synthesis of Troger's base-derived ligandshttps://hdl.handle.net/10355/48210
[2,3]-Sigmatropic rearrangement of propargylic sulfinates ; Regiodivergent synthesis of 1- and 2 arylsulfonyl 1,3-dienes, and III. Synthesis of Troger's base-derived ligands
Hampton, Carissa Sue
[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] The [2,3]-sigmatropic rearrangement of propargylic sulfinates to allenic sulfones was studied under both silver and copper catalysis. Metal salts having non-coordinating anions were effective at promoting the rearrangement. In addition, recoverable and reusable metal-doped ultrastable Y (USY) zeolites are able to catalyze the rearrangement, making the process more environmentally "green". In the course of studying some organometallic chemistry of allenic sulfones, we discovered a facile palladium-catalyzed isomerization of these species to 1-arylsulfonyl 1,3-dienes. In the absence of palladium, but in the presence of a nucleophile and proton shuttle, such allenes can be converted to 2-arylsulfonyl 1,3-dienes. The mechanisms of both processes are examined. Troger?s base is a non-natural chiral amine whose analogues have applications in many areas. The sterics of Troger?s base prevent it from functioning as a bidentate ligand. We have designed a ligand derived from the Troger?s base structural framework that is dianionic and contains multiple coordination sites for transition metal and actinide complexation.
2014-01-01T00:00:00Z